Aquatic Zoos - Captive Animals Protection Society
Aquatic Zoos - Captive Animals Protection Society
Aquatic Zoos - Captive Animals Protection Society
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Sometimes some species may be housed with others because they either look similar, or in the visitor’s<br />
mind they might be living together in the wild, when in reality they never would find each other in their<br />
respective natural habitats. For instance, most Banggai cardinalfish in public and private aquaria (figure<br />
47) are commonly kept with coral reef species, despite the fact that they live in seagrass beds miles<br />
away from coral reefs (Delbeck, 1999). This, although does not necessarily mean that these fish may<br />
suffer from the presence of its unusual companions, does not help public aquaria to fulfil their selfimposed<br />
education role, which should have being considered when designing their exhibits.<br />
Figure 47. Banggai cardinal fish kept in a UK public aquarium tank together with<br />
tropical reef fish species that never would encounter it in the wild.<br />
Although it may seem impossible, sometimes the design of exhibits does not prevent animals in aquaria<br />
from escaping their tanks. In one UK public aquaria in the year 2000 a shark leapt out of its tank twice<br />
and landed among visitors (Anonymous, 2000), and the low walls of the tanks were blamed for the<br />
event.<br />
The materials used in the exhibits or even the chemical procedures to treat the water may also be<br />
chosen wrongly as part of a public aquarium design. Aluminium is acutely toxic to fish and invertebrates,<br />
so it should not be used in the design of tanks. Synthetic salts that may be used in public aquaria are<br />
notorious for containing elevated levels of this element due to impurities (Poléo, 1995).<br />
In fact, metals should not be part of the submerged portion of a tank when species sensitive to electric<br />
fields are housed. In Steinhart aquarium (San Francisco) a young great white shark that was held in a<br />
doughnut-shape tank kept crashing into the wall at the exact spot, and it turned out that some corroded<br />
metal was generating a weak electric current (Bright, 1999).<br />
Ozone is commonly used to disinfect the water of public aquarium systems but it is a powerful oxidant<br />
and can elevate ‘Oxidation Reduction Potential’ (ORP) values to unsafe levels. Several sharks deaths in<br />
UK public aquaria have been blamed on this, not only in published cases (Anonymous, 2001a), but also<br />
in unpublished ones.<br />
Although it is very difficult to measure the actual free volume a shark may have in an aquarium without<br />
having exact measures of its tank (visual references are not good enough to assess size in aquaria due<br />
to the distortion water refraction produces), or to know the actual composition of the aquarium artificial<br />
salt, some display designs can indeed be assessed through a simple visit to the aquarium. In this chapter<br />
we will pay attention to some of them.<br />
95